/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.maven.repository.internal;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Date;
  import java.util.LinkedHashMap;
  import java.util.Map;
  
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.deployment.DeployRequest;
  import org.eclipse.aether.impl.MetadataGenerator;
  import org.eclipse.aether.metadata.Metadata;
  import org.eclipse.aether.util.ConfigUtils;
  
  /**
   * Maven remote GAV level metadata generator.
   * <p>
   * Remote snapshot metadata converts artifact on-the-fly to use timestamped snapshot version, and enlist it accordingly.
   */
  class RemoteSnapshotMetadataGenerator implements MetadataGenerator {
  
      private final Map<Object, RemoteSnapshotMetadata> snapshots;
  
      private final Date timestamp;
  
      RemoteSnapshotMetadataGenerator(RepositorySystemSession session, DeployRequest request) {
          timestamp = (Date) ConfigUtils.getObject(session, new Date(), "maven.startTime");
  
          snapshots = new LinkedHashMap<>();
  
          /*
           * NOTE: This should be considered a quirk to support interop with Maven's legacy ArtifactDeployer which
           * processes one artifact at a time and hence cannot associate the artifacts from the same project to use the
           * same timestamp+buildno for the snapshot versions. Allowing the caller to pass in metadata from a previous
           * deployment allows to re-establish the association between the artifacts of the same project.
           */
          for (Metadata metadata : request.getMetadata()) {
              if (metadata instanceof RemoteSnapshotMetadata) {
                  RemoteSnapshotMetadata snapshotMetadata = (RemoteSnapshotMetadata) metadata;
                  snapshots.put(snapshotMetadata.getKey(), snapshotMetadata);
              }
          }
      }
  
      @Override
      public Collection<? extends Metadata> prepare(Collection<? extends Artifact> artifacts) {
          for (Artifact artifact : artifacts) {
              if (artifact.isSnapshot()) {
                  Object key = RemoteSnapshotMetadata.getKey(artifact);
                  RemoteSnapshotMetadata snapshotMetadata = snapshots.get(key);
                  if (snapshotMetadata == null) {
                      snapshotMetadata = new RemoteSnapshotMetadata(artifact, timestamp);
                      snapshots.put(key, snapshotMetadata);
                  }
                  snapshotMetadata.bind(artifact);
              }
          }
  
          return snapshots.values();
      }
  
      @Override
      public Artifact transformArtifact(Artifact artifact) {
          if (artifact.isSnapshot() && artifact.getVersion().equals(artifact.getBaseVersion())) {
              Object key = RemoteSnapshotMetadata.getKey(artifact);
              RemoteSnapshotMetadata snapshotMetadata = snapshots.get(key);
              if (snapshotMetadata != null) {
                  artifact = artifact.setVersion(snapshotMetadata.getExpandedVersion(artifact));
              }
          }
  
          return artifact;
      }
  
      @Override
      public Collection<? extends Metadata> finish(Collection<? extends Artifact> artifacts) {
          return Collections.emptyList();
      }
  }